Nagella

Question 1

Which muscles are involved in inhalation?

Answer 1

Diaphragm and external Intercostals

Question 2

In emphysema is there high or low compliance? Fibrosis?

Answer 2

Emphysema - high

Fibrosis - low

Question 3

What dos surfactant do?

Answer 3

1) Lowers surface tension by minimizing air-liquid interface. This allows for easier breathing.
2) ensures alveoli don’t collapse

Question 4

Which 2 proteins are utilized in the elastic recoil of the lung?

Answer 4

Elastin - much more distensible than collagen. Mostly involved.
Collagen - less distensible than elastin. Only incorporated once the lung is blown up really large.

Question 5

What two things limit alveolar collapse?

Answer 5

1) surfactant

2) mechanical interdependence

Question 6

Is FRC lower when standing or laying down?

Answer 6

Lying down because the abdomen pushes down on the relaxed diaphragm and I guess forces air out of lungs, thus decreasing FRC.

Question 7

Transmural pressure difference =

Answer 7

Alveolar pressure - intrapleural pressure